This invention lends itself to utilization with the following patents.
______________________________________ U.S. Pat. No. ISSUE DATE INVENTOR ______________________________________ 4,662,806 May 5, 1987 Reed 4,845,828 July 11, 1989 Reed 5,379,505 January 10, 1995 Reed 5,417,532 May 23, 1995 Reed 5,499,892 March 19, 1996 Reed 5,562,371 October 8, 1996 Reed ______________________________________
In procedures that involve repairing cracks in a cylinder head, a drill must be properly oriented with respect to a crack in the head so that each hole in a series of holes can be drilled in the crack at a precise angle as set forth in these patents. Since heads for internal combustion engines have a complex contour, and particularly because crack migration tends to travel along areas of casting crystallization and stress lines which are not linear, precision drilling along a plane normal to a crack entails a series of micro adjustments vis-a-vis the head involving continual reorientation of the drill with respect to the head.
Heretofore, the head was placed such that the crack would be exposed to a craftsman who typically moves around the head. Such a technique is cumbersome since crack repair involves treatment with several drilling or abrading tools coupled with manipulation of the crack via a series of jigs and guides. Accordingly, as the craftsman moved around the head, tools which should be strategically adjacent the craftsman needed to be retrieved.